This proposal is a competing continuation to a 1993 NIH grant entitled "Imaging of Molecules by Oscillator-Coupled Resonance" (R01-RR08820-08), as renewed in 1996 by the Biomedical Technology Program of the National Center for Research Resources. The broad objective of the proposed research is to enable biomedical researchers to routinely, quickly, and easily obtain images showing the full three-dimensional atomic structure of the molecules they are studying, in situ, with all their ligands, cross-links, and glycosylation in place. The technical means by which it is proposed to achieve this goal is called magnetic resonance force microscopy (MRFM). Magnetic resonance force microscopy combines the atomic-scale resolution of scanning probe microscopy with the three-dimensional, nondestructive imaging capacity of magnetic resonance. The proposed specific aims are: (1) to achieve a reliable theoretical understanding of electron and proton spin relaxation and dynamics in the MRFM environment, and (2) to apply this knowledge by demonstrating nanometer resolution in 3D MRFM imaging. Achieving these two specific aims will allow a feasible path to practical molecular imaging to be specified in detail and with confidence. The logical next step will be to launch a coordinated national research initiative for quantum molecular microscopy.